Grip warmer and cylinder 2 misfire

[Devon Dumas]

Hi so i have a 2010 yamaha nytro mtx. I have a code 81 that keeps poping up and a misfire on cylinder 2.

I was riding in deep snow and then code 81 poped up when i was riding also that weekend after a 150mile ride it started to misfire at idle and fluctuate between 1500 rpm and 1000rpm. I didnt think much and ended up blowing a coil the next weekend. The morning after i blew a 20 amp fuse for the ignition. I changed the heated grips check the ohms everything is in spec.. i changed the coil and changed plugs... no shorts in the harness.
Ive tried everything and was wondering if anyone had some answers or similar problems before i burn it
Is there any relay i might or somthing i might be missng
Went threw diag mode and tested heaters individually and they both work my ecu fried itself so i pluged into my other nytro and it clear. So i put it back in mine it was fine for 15 minutes at idle then i hop on and hit the throttle and the code comes back up.
Thanks

 

[Devon Dumas]

So i did diag on all coils and found out ny aftermaket coil was maybe half the spark so put in an oem but still getting a code 81 after put it together but when its not zip tied down its fine no codes. So im thinking a short in the harness somewere

 

[74Nitro]

The only thing I've ever seen fry an ECU was improper coils. Buy from Yamaha or get used OEM

 

[74Nitro]

In addition, I've never seen one of these fail and I've been wrenching Yamaha sleds for a long time.

 

[Dr. FeeLGooD]

behind primary clutch- harness rub on nub on motor mount
https://ty4stroke.com/attachments/dsc02880-jpg.104633/

 

[74Nitro]

behind primary clutch- harness rub on nub on motor mount
https://ty4stroke.com/attachments/dsc02880-jpg.104633/

Nice find, thanks for posting.

 

[Devon Dumas]

So after ripping it apart and chansing the harnes i found two shorts. One yellow red.(grip warmers) and one grey and red(ignition coil 2) they were both worn threw and contacting my frame wich explains the misfire and blowing a coil and code 81. This exposure was directly underneath the top steering post bushing clamp. Had to remove tank and panels and pull down on the harness tucked underneath there is a factory screw that cut threw

Thanks for all the help. Reply for any questions and repost because there is alot of confusion on this toppic